Chair construction

ABSTRACT

A chair back assembly includes a substantially rigid peripheral frame defining a central opening, and a substantially flexible back shell coupled to the peripheral frame and spanning at least a portion of the central opening, wherein a first portion of the back shell is fixed with respect to the frame at a first position, a second portion of the back shell is fixed with respect to the frame at a second position that is different than the first position, a third portion of the back shell is constrained with respect to the frame in at least one direction of motion at a third position located between the first position and the second position, and wherein a fourth portion of the back shell is free from constraint with respect to the frame at a fourth position located between the third position and the second position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/704,018, filed on Sep. 21, 2012, entitled “CHAIRCONSTRUCTION,” U.S. Design patent application No. 29/457,269, filed onJun. 7, 2013, entitled “CHAIR,” U.S. Design patent application No.29/457,254, filed on Jun. 7, 2013, entitled “CHAIR,” and U.S. Designpatent application No. 29/457,251, filed on Jun. 7, 2013, entitled“HANDLE APPARATUS,” the entire disclosures of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a chair construction, and in particularto an office chair construction comprising a back assembly allowingdiffering amounts of flexibility along four separate zones, as well as aback assembly and a seat assembly each covered by upholstery coverings.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is to provide a chair componentassembly that comprises a support component adapted to support a portionof a seated user including a shell member having an outer peripheraledge, the support component further including at least one couplerhaving an interior and an opening facing the outer peripheral edge ofthe shell member, and at least one tab member located substantiallyproximate the opening of the at least one coupler, and an upholsterycover assembly wrapped about at least a portion of the support componentand including an edge that is retained within the interior of the atleast one coupler by the at least one tab member.

Another aspect of the present invention is to provide a chair assemblythat comprises a support component adapted to support a portion of aseated user and including a shell member having a channel and at leastone fastener located within the channel, and an upholstery coverassembly wrapped about at least a portion of the support component andincluding a drawstring located within the drawstring tunnel, wherein thedrawstring is adapted to draw the upholstery cover assembly about thesupport component, and wherein at least one of the drawstring and thedrawstring tunnel are retained within the channel by the at least onecoupler.

Yet another aspect of the present invention is to provide a chaircomponent assembly that comprises a support component adapted to supporta portion of a seated user and including a shell member having anaperture, an upholstery cover assembly wrapped about at least a portionof the support component and including a drawstring located within adrawstring tunnel, wherein the drawstring is adapted to draw theupholstery cover assembly about the support component, and wherein thedrawstring includes at least one free end, and at least one fastenerengaging the aperture of the shell member and securing at least aportion of the at least one free end of the drawstring within theaperture.

These and other features and advantages of the present invention will befurther understood and appreciated by those skilled in the art byreference to the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a chair assembly embodying thepresent invention;

FIG. 2 is a rear perspective view of the chair assembly;

FIG. 3 is a side elevational view of the chair assembly showing a backassembly and a seat assembly in upright and reclined positions, and theseat assembly in retracted and extended positions;

FIG. 4 is an exploded top perspective view of a control assembly and theseat assembly;

FIG. 5 is an exploded bottom perspective view of the control assemblyand the seat assembly;

FIG. 6 is an enlarged perspective view of the area VI, FIG. 4;

FIG. 7A is a cross-sectional front elevational view of the seatassembly;

FIG. 7B is a cross-sectional front elevational view of an alternativeembodiment of the seat assembly;

FIG. 8A is a bottom plan view of the seat assembly;

FIG. 8B is a partial bottom plan view of an alternative embodiment ofthe seat assembly;

FIG. 8C is a partial bottom plan view of another alternative embodimentof the seat assembly;

FIG. 9A is a perspective view of a clip;

FIG. 9B is a perspective view of the clip and seat assembly in anassembled configuration;

FIG. 9C is a perspective view of the clip and seat assembly in anunassembled configuration;

FIG. 10 is an exploded front perspective view of the back assembly;

FIG. 11A is an exploded back perspective view of the back assembly;

FIG. 11B is an exploded back perspective view of an alternativeembodiment of the back assembly;

FIG. 11C is a cross-sectional view of the alternative embodiment of theback assembly;

FIG. 11D is an enlarged view of the area XI D, FIG. 11B;

FIG. 12 is a front perspective view of the back assembly;

FIG. 13A is a cross-sectional side view across the line XIIIA-XIIIA,FIG. 12;

FIG. 13B is a cross-sectional side view across the line XIIIB-XIIIB,FIG. 12;

FIG. 13C is a cross-sectional side view of an alternative embodiment ofthe back assembly;

FIG. 14 is a cross-sectional side view across the line XIV-XIV, FIG. 12;

FIG. 15 is an enlarged perspective view of the area XV, FIG. 11A;

FIG. 16 is an exploded front perspective view of the lumbar assembly;

FIG. 17 is a cross-sectional side view of a lumbar assembly;

FIG. 18A is an enlarged perspective view of an engagement of the lumbarassembly with a back frame assembly;

FIG. 18B is an enlarged perspective, cross-sectional view of a handleassembly and housing of the lumbar assembly;

FIG. 18C is an exploded perspective view of the handle assembly andhousing;

FIG. 19 is an exploded perspective view of an alternative embodiment ofthe back assembly;

FIG. 20 is a perspective view of a structural reinforcement member ofthe alternative back assembly of FIG. 19;

FIG. 21 is a cross-sectional view of a top portion of the alternativeembodiment of the back assembly of FIG. 19;

FIG. 22 is a perspective view of the control assembly;

FIG. 23 is a bottom perspective view of a seat shell and rack member;

FIG. 24 is a side perspective view of an armrest;

FIG. 25 is an exploded view of the armrest;

FIG. 26 is an exploded side perspective view of an armrest;

FIG. 27 is a perspective view of a post showing a first vertical surfaceof the post including detents;

FIG. 28 is a front perspective view of a locking member;

FIG. 29 is a rear perspective view of the locking member of FIG. 28;

FIG. 30 is a fragmentary view of the post and locking member;

FIG. 31 is a fragmentary view of the post, locking member and actuatorrod;

FIG. 32 is a cross-sectional view of the armrest in a locked position;

FIG. 32A is an enlarged fragmentary view of the circled area XXIXA inFIG. 32;

FIG. 33 is a cross-sectional view of the armrest in FIG. 32 shown in anunlocked position;

FIG. 33A is an enlarged fragmentary view of the circled area XXXA inFIG. 33;

FIG. 34 is a cross-sectional view of the armrest in FIG. 32 shown in anunlocked position;

FIG. 34A is an enlarged schematic view of the circled area XXXIA in FIG.34;

FIG. 35 is a cross-sectional view of the armrest in FIG. 32 shown in alocked position;

FIG. 35A is an enlarged schematic view of the circled area XXXIIA inFIG. 35;

FIG. 36 is a perspective view of a chair assembly;

FIG. 37 is a front view of the chair assembly as shown in FIG. 36;

FIG. 38 is first side view of the chair assembly as shown in FIG. 36;

FIG. 39 is a second side view of the chair assembly as shown in FIG. 36;

FIG. 40 is a rear view of the chair assembly as shown in FIG. 36;

FIG. 41 is a top view of the chair assembly as shown in FIG. 36;

FIG. 42 is a bottom view of the chair assembly as shown in FIG. 36;

FIG. 43 is a perspective view of an upper corner of a back assembly of achair;

FIG. 44 is a front view of the upper corner of the back assembly shownin FIG. 43;

FIG. 45 is a side view of the upper corner of the back assembly shown inFIG. 43;

FIG. 46 is a rear view of the upper corner of the back assembly shown inFIG. 43;

FIG. 47 is a top view of the upper corner of the back assembly shown inFIG. 43;

FIG. 48 is a perspective view of a handle apparatus of a lumbar assemblyof a chair assembly;

FIG. 49 is a side view of the handle apparatus as shown in FIG. 48;

FIG. 50 is a rear view of the handle apparatus as shown in FIG. 48;

FIG. 51 is a top view of the handle apparatus as shown in FIG. 48; and

FIG. 52 is a bottom view of the handle apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the invention as oriented in FIG. 1. However, itis to be understood that the invention may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventive conceptsdefined in the appended claims. Hence, specific dimensions and othercharacteristics relating to the embodiments disclosed herein are not tobe considered as limiting, unless the claims expressly state otherwise.Various elements of the embodiments disclosed herein may be described asbeing operably coupled to one another, which includes elements eitherdirectly or indirectly coupled to one another.

The reference numeral 10 (FIGS. 1 and 2) generally designates a chairassembly embodying the present invention. In the illustrated example,the chair assembly 10 includes a castered base assembly 12 abutting andsupported by a floor surface 13, a control or support assembly 14supported by the castered base assembly 12, a seat assembly 16 and aback assembly 18 each operably coupled with the control assembly 14, anda pair of arm assemblies 20. The seat assembly 16 (FIG. 3) and the backassembly 18 are operably coupled with the control assembly 14 such thatthe back assembly 18 is movable between a fully upright position A and afully reclined position B, and further such that the seat assembly 16 ismovable between a fully upright position C and a fully reclined positionD corresponding to the fully upright position A and the fully reclinedposition B of the back assembly 18, respectively.

The base assembly 12 includes a plurality of pedestal arms 21 radiallyextending and spaced about a hollow central column 22 that houses apneumatic cylinder therein for adjusting the overall vertical height ofthe control assembly 14, the seat assembly 16 and the back assembly 18above the floor surface 13. Each pedestal arm 21 is supported above thefloor surface 13 by an associated caster assembly 24. Although the baseassembly 12 is illustrated as including a multiple-arm pedestalassembly, it is noted that other suitable supporting structures may beutilized, including but not limited to fixed columns, multiple legarrangements, vehicle seat support assemblies, and the like.

The seat assembly 16 (FIGS. 4 and 5) includes a seat shell member 30having a forward edge 32, a rearward edge 34, and a pair of side edges36 extending between the forward edge 32 and the rearward edge 34,wherein the forward edge 32, the rearward edge 34 and the side edges 36cooperate to form an outer periphery of the seat shell member 30. In theillustrated example, the seat shell member 30 comprises an integrallymolded plastic unitary member, however, other suitable structures andmaterials may also be utilized. The seat shell member 30 furtherincludes a downwardly opening channel 38 having a C-shapedcross-sectional configuration and extending about the periphery of theseat shell 30. A plurality of couplers 40 (FIG. 6) are integral with theseat shell 30, and are located within and spaced along the channel 38.Each coupler 40 includes a pair of ribs 42 each having a downwardlyangled abutment surface 44. Each coupler 40 further includes a flexiblyresilient engagement tooth 46 interspaced with the pair of ribs 42. Theseat assembly 16 further includes a foam cushion member 48 having aforward edge 50, a rearward edge 52, and a pair of side edges 54extending therebetween, wherein at least the forward edge 50, and theside edges 54 of the cushion member 48 cooperate to form a downwardlyopening pocket 56 that receives a portion of the seat shell 30 therein.The seat assembly 16 further includes an upholstery cover assembly 58.In the illustrated example, the cover assembly 58 includes a cover 60comprising a stretchable fabric and including an upper portion 62 and aplurality of side portions 64 extending about the upper portion 62 andwhich cooperate to define an interior space 66 that receives an assemblyof the seat shell 30 and the cushion member 48 therein. The coverassembly 58 further includes a drawstring tunnel 68 extending about aperipheral edge of the side portions 64 and receiving a drawstring 70therein, wherein the drawstring 70 includes a pair of free ends 72extending from the drawstring tunnel 68.

In assembly, the seat shell 30 (FIG. 7A) and the cushion member 48 arelocated within the interior space 66 of the upholstery cover assembly 58such that the drawstring tunnel 68 (FIG. 8A) and the drawstring 70 arelocated within the channel 38 and such that the drawstring tunnel 68 anddrawstring 70 impinge upon the ribs 42 and are engaged by the teeth 46,thereby securing the drawstring tunnel 68 and the drawstring 70 withinthe channel 38.

As best illustrated in FIG. 8A, the free ends 72 of the drawstring 70are secured to the seat shell 30 by a fastener or clip member 80 (FIG.9A). In the illustrated example, the clip member 80 is a spring cliphaving U-shaped spring body 82 having engagement teeth 84 spaced alongthe length thereof, and a pair of flanges 86 extending outwardly fromthe sides of the U-shaped spring body 82. In assembly, the clip 80(FIGS. 8B and 8C) is vertically aligned with a respective free end 72 ofthe drawstring 70, and is then inserted into a portion of the channel 38of the seat shell 30, thereby holding the free end 72 of the drawstring70 within the channel 38. Alternatively, the clip member 80 (FIG. 8A)can engage a separate aperture 88 within the seat shell member 30,thereby securing at least a portion of the free end 72 of the drawstring70 within the aperture 88. Alternatively, multiple clip members 80 (FIG.8B) may be used to secure one of the free ends 72 of the drawstring 70within the channel 38. As best illustrated in FIG. 8C, anotheralternative embodiment includes the securement of two free ends 72 of adrawstring 70 by a single clip 80.

The reference numeral 16 a (FIG. 7B) generally designates anotherembodiment of the seat assembly. Since the seat assembly 16 a is similarto the previously described seat assembly 16, similar parts appearing inFIG. 7B and FIG. 7A, respectively, are represented by the same,corresponding reference numeral, except for the suffix “a” in thenumerals of the latter. In the illustrated example, the seat assembly 16a includes the seat shell 30 a and the cushion member 48 a locatedwithin the interior space 66 a of the upholstery cover assembly 58 asuch that a stile or extrusion 73 a is located within the channel 38 a,thereby securing the cover assembly 58 a to the seat shell 30 a. Asillustrated, the elastically deformable extrusion 73 a has a J-shapedcross-sectional configuration, including a hook portion 75 a thatsnappingly engages the teeth 46 upon insertion of the extrusion 73 ainto the channel 38 a. The cover 60 a is preferably sewn to theextrusion 73 a, however, other suitable connection methods may also beutilized.

The back assembly 18 (FIGS. 10 and 11) includes a substantially rigidperipheral frame 90 that includes a laterally extending top portion 92,a laterally extending bottom portion 94, and a pair of verticallyextending side portions 96, wherein the top portion 92, the bottomportion 94 and the side portions 96 cooperate to form a central opening98. The back assembly 18 further includes a lumbar support assembly 100adapted to support a lumbar area of a seated user and received withinslots 102 extending vertically along each of the side portions 96 of theperipheral frame 90. A pair of side extensions 104 extend verticallyalong and are received within pockets 106 of the side portions 96 andare secured thereto by a plurality of mechanical fasteners 107.

The back assembly 18 further includes a substantially flexible backshell 108 including a top portion 110, a bottom portion 112, and a pairof side portions 114 that align with the top portion 92, the bottomportion 94 and the side portions 96 of the peripheral frame 90,respectively and as described below. The back shell 108 further includesa plurality of vertically spaced slats 116 extending between the sideportions 114 and defining a plurality of slots 118 therebetween. Inassembly, the back shell 108 (FIG. 12) is attached to the peripheralframe 90 in such a manner so as to define vertically spaced zones orregions of differing flexibility for the back shell 108. Specifically,the back shell 108 is attached to the peripheral frame 90 such that atop region 120 and a bottom region 122 of the back shell 108 are fixedwith respect to the peripheral frame 90, a third region 124 of the backshell 108 is constrained with respect to the peripheral frame 90 in aforward direction, and a fourth region 126 of the back shell 108 is freeto separate from the peripheral frame 90 in a forward direction, whereinthe flexed state of the back shell 108 is shown in dashed line. Morespecifically, and as best illustrated in FIGS. 13A and 13B, the topportion 92 of the peripheral frame 90 includes a plurality ofupwardly-extending hooks 130 integral with and spaced across the topportion 92, while the top portion 110 of the back shell 108 includes aplurality of downwardly-extending flexibly resilient loops 132 integralwith the top portion 110, wherein the hooks 130 engage the loops 132,thereby flexing the loops 132 in a direction 133 during engagement andfixedly securing the top portion 110 of the back shell 108 to the topportion 92 of the peripheral frame 90. As best illustrated in FIG. 12,the back shell 108 includes a pair of integral tab members 134 locatedat the intersection of the side portions 114 and the bottom portion 112,wherein the tab members 134 are secured to peripheral frame 90 bymechanical fasteners such as bolts 136, thereby fixedly securing thebottom portion 112 of the back shell 108 to the bottom portion 94 of theperipheral frame 90. As best illustrated in FIG. 14, the third region124 of the back shell 108 includes rearwardly and downwardly extendinghooks 140 located along the length and integral with the side portions114 of the back shell 108. Each hook 140 is received within a pocket 142formed between the side extensions 104 and the side portions 96, suchthat the back shell 108 is pivotable about a pair of axis 144 extendingvertically through the corresponding hooks 140. The pockets 142 locatedwithin the third region 124 are also sized so as to allow lateraldisplacement of the hooks 140 within the pockets 142 in a direction 146so as to allow the side portions 114 of the back shell 108 to flexinwardly with respect to the side portions 96 of the peripheral frame 90thereby in turn, allowing increased flexibility and compliance of theback shell 108 in a rearward direction 148 with respect to theperipheral frame 90. The side portions 114 of the back shell 108 locatedwithin the fourth region 126 are not secured to the side portions 96 ofthe peripheral frame 90, thereby allowing maximum compliance andflexibility of the back shell 108 with respect to the peripheral frame90 in both the lateral direction 146 and in the rearward direction 148.As a result, the first and second regions 120, 122 of the back shell 108are constrained from movement with respect to the peripheral frame 90,the third region 124 allows limited compliance of the back shell 108with respect to the frame 90, while the fourth region 126 allows formaximum flexure of the back shell 108 with respect to the frame 90.

The reference numeral 18 b (FIG. 11B) generally designates anotherembodiment of the back assembly. Since the back assembly 18 b is similarto the previously described back assembly 18, similar parts appearing inFIGS. 11B and 11A, respectively, are represented by the same,corresponding reference numeral, except for the suffix “b” in thenumerals of the latter. In the illustrated example, the upholstery coverassembly 150 b includes a drawstring 160 b and a plurality of stiles orextrusions 151 b attached to and extending along the side portions 154 bof the cover assembly 150 b. As best illustrated in FIG. 11C, eachextrusion 151 b has a J-shaped cross-sectional configuration that issecured to the cover assembly 150 b via a stitch 153 b, and thatincludes a hook portion 155 b that engages the teeth 168 b of thecouplers 162 b of the back shell 108 b. The drawstring 160 b is locatedwithin a drawstring tunnel 158 b that is secured to the associated sideportion 154 b via a stitch 157 b and is drawn about the back shell 108 bsubsequent to the extrusions 151 b being secured to the back shell 108b. The free ends 163 b of the drawstring 160 b are secured to oneanother via a ferrule 165 b. In the illustrated example, the drawstring160 b is relatively incompressible and is comprised of a single strandpolypropylene material, although materials such as nylon as well asmultistrand constructions may also be utilized.

The reference numeral 18 c (FIG. 19) generally designates anotherembodiment of the back assembly. Since the back assembly 18 c is similarto the previously described back assembly 18, similar parts appearing inFIG. 10 and FIG. 19 are identified by the same, corresponding referencenumerals except for the suffix “c” in the numerals of the latter. In theillustrated example, the back assembly 18 c includes a rigid back frame90 c, a top cover member 500 covering an upper portion of the back shell108 c that includes an upper portion 502 and a separate lower portion504. A plate member 506 (FIGS. 20 and 21) extends laterally across theupper portion 92 c of the back frame 90 c and is positioned between theupper portion 92 c of the back frame 90 c and the back shell 108 c, asdescribed below. As best illustrated in FIGS. 20 and 21, the platemember 506 includes an elongated body portion 510, a pair of outwardlylocated, forwardly-extending alignment tabs 512, a pair offorwardly-extending connection tabs 514, a centrally positioned,forwardly-extending alignment tab 516, and a plurality ofrearwardly-extending engagement tabs 518. Each of the alignment tabs512, the connection tabs 514 and the alignment tabs 516 are receivedwithin corresponding apertures 520 (FIG. 21) formed between the upperportion 502 and the lower portion 504 of the back shell 108 c.

As best illustrated in FIG. 21, the upholstery assembly 150 c includes afabric or mesh fabric 522, and a thin foam layer 522. The plate member506 (FIG. 21) is positioned such that an edge of the fabric 522 istrapped between the plate member 506 and the lower portion 504 of theback shell 108 c, and the plate member 506 is then heat staked to thelower portion 504 of the back shell 108 c and separately to the upperportion 502 of the back shell 108 c, thereby structurally coupling theupper portion 502 to the lower portion 504 through the plate member 506.It is noted that the structurally reinforcing plate member 506 iscoupled to the back frame 90 c subsequent to the fabric 522 beingsecured about the back shell 108 c. The back shell 108 c is secured tothe back frame 90 c by engaging each of the engagement tabs 518 into acorresponding groove 528 located within the upper portion 92 c of theback frame 90 c, such that the plate member 506 properly aligns the backshell 108 c with the back frame 90 c assuring proper fit and finish forthe aesthetics of the chair.

The back assembly 18 further includes a back upholstery cover assembly150 having a front portion 152 and a plurality of side portions 154 thatcooperate to form an interior space 156 that receives the back shell 108therein. The upholstery assembly 150 is comprised of a stretchablefabric material and includes a drawstring tunnel 158 that extends aboutan inner periphery of the side portions 154 and houses a drawstring 160therein. As best illustrated in FIG. 13A, the upholstery assembly 150receives a portion of the back shell 108. Alternatively, the upholsteryassembly 150′ (FIG. 13C) extends about a portion of the back shell 108′,a foam cushion member 155′, and an inner fabric layer 157′ whichseparates the cushion member 155′ from the back shell 108′.

As best illustrated in FIGS. 13A and 15, the back shell 108 includes aplurality of couplers 162 spaced about the periphery of the back shell108. In the illustrated example, each coupler 162 includes a pair ofoutwardly-extending fingers 164 that are formed so as to define anopening facing an outer peripheral edge 166 of the back shell 108. Aplurality of flexibly resilient teeth 168 are interdigitated with thefingers 164 of the coupler 162. In assembly, the upholstery assembly 150wraps about the edges of the back shell 108 such that the drawstringtunnel 158 and the drawstring 160 are received within the couplers 162and engaged by the teeth 168, thereby retaining the drawstring tunnel158 and the drawstring 160 within the associated couplers 162.

The lumbar assembly 100 (FIGS. 10, 11A and 16) includes a body shell 200housing a laterally extending decorative plate 202, a pair of lateralextending leaf springs 203, a pair of sliding connection assemblies 204,and a pair of adjustment handles 205 configured for grasping by a userto move the lumbar assembly 100 between a lowered position E (FIG. 2)and a raised position F. The molded body shell 200 includes a frontportion 206 and a back portion 208 arcuately shaped and vibrationallywelded to one another in a back-to-back relationship to form a pocket210 (FIG. 17) which receives the decorative plate 202 therein.Alternatively, other methods of coupling the front and back portions206, 208 may be utilized, including mechanical fasteners such as screws,snaps, ultra sonic welding, adhesives, and the like. The leaf springs203 extend along the length of the body shell 200 and are located withinrespective pockets 212 juxtaposed from one another across the pocket210. The leaf springs 203 are adapted to provide a forward biasing forceagainst a rearward force exerted by a lumbar area of a seated user'sback. The sliding connection assemblies 204 are attached to the ends ofthe lumbar assembly 100 and are slidably received with an elongatedrelief 218 (FIG. 18A) formed between the receptive side portion 96 ofthe peripheral frame 90 and the side extensions 104, such that thelumbar assembly 100 is vertically movable between the lowered and raisedpositions E, F. Specifically, the body shell 200 includes a pair ofvertically extending ribs 219 that guide along the respective sideextensions 104, thereby centering the lumbar assembly 100 with respectto the frame 90. It is noted that the relative width of peripheral frame90 changes along the path the lumbar assembly 100 travels whenvertically adjusted, thereby requiring a sliding connection between thesliding connection assemblies 204 and the body shell 200. As bestillustrated in FIG. 18B, each end of the front portion 206 of the bodyshell 200 includes a pair of barrel-headed tabs 220 slidably receivedwithin a pair of corresponding slots 222 which allows for slidingadjustment between the connection assemblies 204 and the body shell 200while preventing the body shell 200 from disengaging the connectionassemblies 204. In assembly, and as best illustrated in FIGS. 12A and18C, each handle 205 includes a blade portion 207 that is slidablyreceived within a corresponding pocket 209 of the connection assembly204 and is held therein by a flexibly resilient tab 211 that engages anaperture 213 of the blade portion 207, thereby slidably securing thelumbar assembly 100 within the slots 102. Each connection assembly 204further includes a flexibly resilient bar 217 with a pawl member 219that selectively engages a plurality of detents 221 (FIG. 10) verticallyspaced along the side portion 102 of the frame 90, thereby holding thelumbar assembly 100 in a selected vertical position with respect to theframe 90.

As best illustrated in FIG. 3, the seat assembly 16 is movable between aretracted position G and an extended position H, thereby providing depthadjustment for the chair assembly 10. The seat assembly 16 (FIGS. 4 and5) is slidably supported on the control assembly 14. The controlassembly 14 (FIG. 22) includes support plates 251, 252 disposed onopposite sides of the overall control assembly 14. The control assembly14 further includes an actuator bar 253 which is generally U-shaped andincludes a handle portion 254 disposed under a front portion of the seatassembly 16 and adapted to be grasped by a user, and a pair of armportions 255 extending rearwardly from the handle portion 254. Uponactuating the actuator bar 253, the handle portion 254 is lifted upwardin a direction 256, wherein the actuator bar 253 pivots in the seatshell 30 at pivot point 257 which causes the distal ends 258 of the armportions 255 to move downward in a direction 259 to engage correspondingrockers 260 which are pivotably connected to the seat shell 30 aboutpivot axis 261. The actuation of the actuator bar 253 moves the rockers260 from an engaged position to a disengaged position, thereby allowingmovement of the seat assembly 16 between the retracted and extendedpositions G, H. Specifically, the rockers 260 selectively engage aplurality of reliefs 262 of corresponding racks 263, thereby allowingthe seat assembly 16 to be selectively locked at positions between theretracted and extended positions.

As shown in FIGS. 7A and 23, the bottom surface 265 of the seat shell 30includes a downwardly opening integral linear guide bearing channel 266extending front-to-back of the seat shell 30. As best illustrated inFIG. 20, the support plate 252 includes a pair of upwardly-extendingguide portions 270 that slidably track within the linear bearing 266 ofthe seat shell 30, thereby linearly guiding the seat shell 30 withrespect to the support plate 252 and the overall control assembly 14.The support plate 252 includes an L-shaped guide portion 290 (FIG. 22)housed in a bearing member 291, which is received within a correspondinginwardly-opening slot 292, such that the guide portion 290 of thesupport plate 252 guides within the slot 292 as the seat assembly ismoved between the retracted and extended positions G, H.

Alternatively, a removable stop member 293 may be secured to anunderside of the seat shell 30 at a position such that the stop memberabuts a portion 295 of the support plate 251, thereby limiting theamount of travel of the seat assembly 16 from the extended position tothe retracted position and preventing the seat assembly 16 from movingto the rearward-most position. In the illustrated example, the stopmember 293 is secured to the seat shell 30 via a screw 297, therebyrequiring the use of a tool for installation and removal.

Each armrest assembly 20 (FIGS. 3, 24 and 25) is vertically adjustablebetween a raised position I and a lowered position J and includes atubular support 300 constructed for attachment to a chair 10, an armrestassembly 302 telescopingly positioned in the tubular support, and aheight adjustment mechanism 304 slidably received in the armrestassembly. A plate 306 is attached to the top of the armrest assembly 302and an arm cap 308 is attached to the plate 306. In an alternativeembodiment, a pivot/slide member 309 may be attached to the plate andthe arm cap 308 attached to the pivot/slide member. The pivot/slidemember is similar to that disclosed in co-assigned U.S. Pat. No.5,971,484, filed Dec. 3, 1997, entitled “ADJUSTABLE ARMREST FOR CHAIRS,”the contents of which are incorporated herein by reference for itsteachings.

Referring to FIGS. 25 and 26, the tubular support 300 includes anL-shaped structural member having a horizontal first arm section 310adapted for connection to the fixed side support structures, and avertically extending second arm section 312. The second arm section 312includes an upper opening 314 for telescopingly receiving the armrestassembly 302, a lower opening 316, and a groove 318 including afastening aperture 319, along one vertical side. When the armrestassembly 302 is inserted into the second arm section 312, the lowerportion of a sleeve 320 extends through the lower opening 316 and isvisible. As the armrest assembly is vertically adjusted upward, thesleeve becomes less visible. The groove 318 and the lower opening 316are on opposite sides of the second arm section 312.

The armrest assembly 302 is telescopingly received in the tubularsupport 300 and includes a sleeve 320, a post 321, and may also includea bearing 322. The sleeve 320 includes a first side 324 and a secondside 326. The first side 324 may include an aperture 328 near the lowerend of the first side. Near the top of the first side 324 is an opening330 which is adapted to receive an operative member 370 of an actuatorrod 334. The sleeve 320 flares out at the top to provide an armrestsupport 336. The second side 326 of the sleeve 320 includes arectangular aperture 338 at the lower end of the second side. On eitherside of the aperture 338 is a vertical rib 340 and a vertical rib 341,wherein the vertical rib 341 is significantly longer than the verticalrib 340, thereby increasing the overall effective length of the ribs340, 341, and preferably provides a length l to width w ratio of atleast 3:1, and is preferably at least 10:1, thereby reducing thefore-to-aft shifting of the armrest assembly 302 within the tubularsupport 300. Referring to FIGS. 25 and 26, the post 321 is rectangularwith a lip 342 on its top end and a tab 344 on the bottom end. The postalso includes a first vertical surface 346 and a second vertical surface348. The first vertical surface 346 includes a series of positionaldetents 350 and a fastening aperture 352 (FIG. 27). The fasteningaperture 352 extends completely through the post 321 to the secondvertical surface 348. On either side of the positional detents 350 arevertical grooves 354, wherein one of the grooves 354 extends through thebottom of the post 321, and wherein the grooves 354 mateably receive thevertical ribs 340, 341 on the sleeve 320 to prevent complete removal ofthe armrest assembly 302 from the tubular support 300. Specifically, inthe illustrated example, one of the channels in 354 includes an endwall356 that is abutted by a corresponding rib 340, thereby preventingremoval of the arm rest assembly 302 from the tubular support 300. Theremaining groove 354 extends through the end of the post 321 to allowpassage of the secondary vertical rib 341. The second vertical surface348 includes ridges 358. The bearing 322 provides a bearing surface andincludes two collars 360 which are connected to a vertical strip 362 attheir midpoints. Although FIGS. 25 and 26 show the collars 360 as angledrelative to each other, in an alternative embodiment, the collars areparallel relative to each other. The ends 364 of the collars 360 flareoutwardly to define a space 366.

The post 321 is mateably received in the groove 318 of the second armsection 312, with the second vertical surface 348 abutting the secondarm section 312. A fastening means is inserted through fasteningaperture 319 and into fastening aperture 352 to secure the post 321 inthe groove 318. Alternatively, it is contemplated that the post 321 isnot a separate piece fastened in the groove 318, but rather molded intothe second arm section 312. When the sleeve 320 is inserted into thesecond arm section 312, the first vertical surface 346 of the post 321abuts the second side 326 of the sleeve. Also, the detents 350 on thefirst vertical surface 346 of the post 321 cover the aperture 338 on thesecond side 326 of the sleeve 320. The vertical ribs 340, 341 on thesecond side 326 of the sleeve 320 mate with the vertical grooves 354 ofthe post 321 so that the positional detents 350 remain positioned overthe aperture 338 when the sleeve is adjusted vertically. The bearing 322is positioned on the sleeve 320 with the vertical strip 362 abutting thefirst side 324 of the sleeve 320, allowing the collars 360 to wraparound the sleeve 320. The post 321 fits between the collar ends 364 inthe space 366. The bearing 322 is stationary within the second armsection 312 and functions to limit horizontal movement of the sleevewithin the tubular support.

The height adjustable mechanism 304 comprises the actuator rod 368 thatincludes the operative member 370, a locking member 372, and a spring374. In the illustrated example, the operative member 370 is located atthe top of the actuator rod 368 and is generally perpendicular to anelongated portion 378 of the actuator rod 368. As shown, the operativemember 370 is a lever, however, it is contemplated that a button or tabcould be used. Attached to the operative member 370 is a flange 380. Onthe other side of the flange 380 is a ledge 382 having a protrusion 384.When the height adjustable mechanism 304 is slidably engaged with thearmrest assembly 302, the actuator rod 368 is positioned inside thesleeve 320 with the operative member 370 positioned through aperture330. One end of the spring 374 is placed over the protrusion 384, withthe opposite end of the spring 374 placed over a protrusion 386 on theunderside of the plate 306. Located at the bottom of the actuator rod334 (FIG. 33) are two angled ramps 388 which resemble hooks. The angledramps 388 prevent the locking member 372 from falling to the bottom ofthe sleeve 320. Above each angled ramp 388 is at least one angledsurface, and preferably a pair of angled surfaces 390. Between the pairof angled surfaces 390 is an inclined wedge 392.

As best seen in FIGS. 28-30, the locking member 372 includes teeth 394that selectively mateably engage the detents 390 on the post 321. Thelocking member 372 also includes an inclined surface 396 that mates withthe inclined wedge 392. The locking member 372 also includes at leastone pair, and preferably two pairs of lateral followers 398 whichreleasably mateably engage the two pairs of angled surfaces 390.

The height adjustable mechanism 304 is slidably engaged within thesleeve 320. When in a locked position, the locking member 372 of theheight adjustable mechanism 304 is positioned such that the teeth 394 ofthe locking member extend through aperture 338 of the sleeve 320 andselectively mate with the detents 350 of the post 321. The actuator rod368 is positioned over the locking member 372 with the inclined wedge392 mateably engaged with the inclined surface 396 and the angledsurfaces 390 releasably mateably engaged with the lateral followers 398(FIGS. 31, 32 and 32A).

To vertically adjust the height of the armrest, the operative member 370is lifted upward, which in turn, compresses the spring 374. When thespring compresses, the angled surfaces 390 of the actuator rod 368 liftupward and push on the lateral followers 398, which causes the teeth 394to withdraw into the sleeve 320, thereby removing the locking member 372from locking engagement with the detents 350 (FIGS. 33 and 33A). Oncethe locking member 372 is disengaged from the detents 350, the armrestcan be vertically adjusted upward or downward to a desired height.

To reengage the locking member 372 and relock the armrest in a selectedposition, the operative member 370 is released, thereby decompressingthe spring 374 at the top of the actuator rod 368. Decompression of thespring causes the inclined wedge 392 to slide into mateable engagementwith the inclined surface 396. (FIGS. 34, 34A, 35 and 35A). As theinclined wedge 392 and inclined surface 396 are mateably engaged, theteeth 394 of the locking member again extend through the aperture 338and selectively mate with the detents 350 of the post 321.

An embodiment of a chair assembly is illustrated in a variety of views,including a perspective view (FIG. 36), a front elevational view (FIG.37), a first side elevational view (FIG. 38), a second side elevationalview (FIG. 39), a rear elevational view (FIG. 40), a top plan view (FIG.41), and a bottom plan view (FIG. 42). A portion of an embodiment of aback assembly is illustrated in a variety of views, including aperspective view (FIG. 43), a front elevational view (FIG. 44), a sideelevational view (FIG. 45), a rear elevational view (FIG. 46), and a topplan view (FIG. 47). An embodiment of an adjustment handle isillustrated in a variety of views, including a perspective view (FIG.48), a side elevational view (FIG. 49), a front elevational view (FIG.50), a top view (FIG. 51), and a bottom view (FIG. 52).

In the foregoing description, it will be readily appreciated by thoseskilled in the art that alternative combinations of the variouscomponents and elements of the invention and modifications to theinvention may be made without departing from the concepts as disclosed.Such modifications are to be considered as included in the followingclaims, unless these claims by their language expressly state otherwise.

The invention claimed is:
 1. A chair back assembly, comprising: asubstantially rigid peripheral frame defining a central opening; and asubstantially flexible back shell coupled to the peripheral frame andspanning at least a portion of the central opening, wherein a firstportion of the back shell is fixed with respect to movement in a lateraldirection, in a vertical direction and in a forward and rearwarddirection with respect to the frame at a first position, a secondportion of the back shell is fixed with respect to movement in a lateraldirection, in a vertical direction and in a forward and rearwarddirection with respect to the frame at a second position that isdifferent than the first position, a third portion of the back shell isconstrained with respect to the frame in at least one direction ofmotion at a third position located between the first position and thesecond position, and wherein a fourth portion of the back shell is freefrom constraint with respect to the frame in a lateral direction and ina forward and rearward direction at a fourth position located betweenthe third position and the second position such that the fourth portionof the back shell is flexible in at least the lateral direction.
 2. Thechair back assembly of claim 1, wherein the first portion of the backshell is located substantially proximate an upper edge of the backshell.
 3. The chair back assembly of claim 2, wherein the second portionof the back shell is located substantially proximate a lower edge of theback shell.
 4. The chair back assembly of claim 3, wherein the fourthposition of the back shell is adapted to support a lumbar area of aseated user.
 5. The chair back assembly of claim 4, wherein the at leastone direction of motion at the third position includes a forwarddirection with respect to the frame.
 6. The chair back assembly of claim5, wherein at least one of the frame and the back shell includes a hookmember, the other of the at least one of the frame and the back shellincludes a slot that receives the hook member such that the hook islaterally displaceable within the slot and pivotable within the slotabout a lateral axis extending across the width of the frame.
 7. Thechair back assembly of claim 6, wherein the hook member and the slotcooperate to limit lateral displacement of an edge of the back shellwith respect to the frame at the third location to less than a lateraldisplacement of the edge of the back shell with respect to the frame atthe fourth location.
 8. The chair back assembly of claim 6, wherein thehook member is integral with the back shell.
 9. The chair back assemblyof claim 1, wherein the at least one direction of motion at the thirdposition includes a forward direction with respect to the frame.
 10. Achair back assembly, comprising: a substantially rigid peripheral framedefining a central opening; and a substantially flexible back shellcoupled to the peripheral frame and spanning at least a portion of thecentral opening, wherein a first portion of the back shell is fixed withrespect to movement in a lateral direction, in a vertical direction andin a forward and rearward direction with respect to the frame at a firstposition, a second portion of the back shell is fixed with respect tothe frame at a second position that is different than the firstposition, a third portion of the back shell is constrained with respectto the frame in at least one direction of motion at a third positionlocated between the first position and the second position, and whereina fourth portion of the back shell is free from constraint with respectto the frame in a lateral direction and in a forward and rearwarddirection at a fourth position located between the third position andthe second position; wherein at least one of the frame and the backshell includes a hook member, the other of the at least one of the frameand the back shell includes a slot that receives the hook member suchthat the hook is laterally displaceable within the slot and the backshell is pivotable about a vertical axis extending through the hookmember.
 11. The chair back assembly of claim 10, wherein hook member andthe slot cooperate to limit lateral displacement of an edge of the backshell with respect to the frame at the third location to less than alateral displacement of the edge of the back shell with respect to theframe at the fourth location.
 12. The chair back assembly of claim 10,wherein the hook member is integral with the back shell.
 13. A chairassembly, comprising: a support assembly adapted to contact a floorsurface; a seat assembly operably coupled to the support assembly andadapted to support a seated user thereon; and a chair back assembly,comprising: a substantially rigid peripheral frame defining a centralopening; and a substantially flexible back shell coupled to theperipheral frame and spanning at least a portion of the central opening,wherein a first portion of the back shell is fixed with respect tomovement in a lateral direction in a vertical direction and in a forwardand rearward direction with respect to the frame at a first position, asecond portion of the back shell is fixed with respect to movement in alateral direction, in a vertical direction and in a forward and rearwarddirection with respect to the frame at a second position that isdifferent than the first position, a third portion of the back shell isconstrained with respect to the frame in at least one direction ofmotion at a third position located between the first position and thesecond position, wherein the back shell is free from constraint withrespect to the frame in a lateral direction and in a forward andrearward direction at a fourth position located between the thirdposition and the second position, and wherein laterally-spaced portionsof the fourth portion move toward one another as a rearwardly directedforce is applied to the fourth portion.
 14. The chair assembly of claim13, wherein the first portion of the back shell is located substantiallyproximate an upper edge of the back shell.
 15. The chair assembly ofclaim 14, wherein the second portion of the back shell is locatedsubstantially proximate a lower edge of the back shell.
 16. The chairassembly of claim 15, wherein the fourth position of the back shell isadapted to support a lumbar area of a seated user.
 17. The chairassembly of claim 16, wherein the at least one direction of motion atthe third position includes a forward direction with respect to theframe.
 18. The chair assembly of claim 17, wherein at least one of theframe and the back shell includes a hook member, the other of the atleast one of the frame and the back shell includes a slot that receivesthe hook member such that the hook is laterally displaceable within theslot and the back shell is pivotable about a vertical axis extendingthrough the hook member.
 19. The chair assembly of claim 18, wherein thehook member and the slot cooperate to limit lateral displacement of anedge of the back shell with respect to the frame at the third locationto less than a lateral displacement of the edge of the back shell withrespect to the frame at the fourth location.
 20. The chair assembly ofclaim 18, wherein the hook member is integral with the back shell. 21.The chair assembly of claim 13, wherein the at least one direction ofmotion at the third position includes a forward direction with respectto the frame.
 22. A chair assembly, comprising: a support assemblyadapted to contact a floor surface; a seat assembly operably coupled tothe support assembly and adapted to support a seated user thereon; and achair back assembly, comprising: a substantially rigid peripheral framedefining a central opening; and a substantially flexible back shellcoupled to the peripheral frame and spanning at least a portion of thecentral opening, wherein a first portion of the back shell is fixed withrespect to movement in a lateral direction in a vertical direction andin a forward and rearward direction with respect to the frame at a firstposition, a second portion of the back shell is fixed with respect tothe frame at a second position that is different than the firstposition, a third portion of the back shell is constrained with respectto the frame in at least one direction of motion at a third positionlocated between the first position and the second position, and whereinthe back shell is free from constraint with respect to the frame in alateral direction and in a forward and rearward direction at a fourthposition located between the third position and the second position;wherein at least one of the frame and the back shell includes a hookmember, the other of the at least one of the frame and the back shellincludes a slot that receives the hook member such that the hook islaterally displaceable within the slot and the back shell is pivotableabout a vertical axis extending through the hook member.
 23. The chairassembly of claim 22, wherein hook member and the slot cooperate tolimit lateral displacement of an edge of the back shell with respect tothe frame at the third location to less than a lateral displacement ofthe edge of the back shell with respect to the frame at the fourthlocation.
 24. The chair assembly of claim 22, wherein the hook member isintegral with the back shell.
 25. The chair assembly of claim 13,further comprising: a lumbar support assembly abutting the fourthposition of the back shell and adapted to support a lumbar area of aseated user.
 26. A chair assembly, comprising: a support assemblyadapted to contact a floor surface; a seat assembly operably coupled tothe support assembly and adapted to support a seated user thereon; and achair back assembly, comprising: a substantially rigid peripheral framedefining a central opening and a recess extending about at least aportion of the central opening; and a substantially flexible back shellcoupled to the peripheral frame and spanning at least a portion of thecentral opening, wherein a first portion of the back shell is fixed withrespect to movement in a lateral direction, in a vertical direction andin a forward and rearward direction with respect to the frame at a firstposition, a second portion of the back shell is fixed with respect tomovement in a lateral direction in a vertical direction and in a forwardand rearward direction with respect to the frame at a second positionthat is different than the first position, the back shell is free fromconstraint with respect to the frame in a lateral direction and in aforward and rearward direction at a third position located between thefirst position and the second position, wherein the back shell ispositioned within the recess of the frame, and wherein laterally-spacedportions of the fourth portion move laterally toward one another as arearwardly directed force is applied to the fourth portion.
 27. Thechair assembly of claim 26, wherein the back shell is constrained withrespect to the frame in at least one direction of motion at a fourthposition located between the first position and the second position. 28.The chair assembly of claim 26, wherein the first portion of the backshell is located proximate a top of the back shell, and wherein thesecond portion of the back shell is located proximate a bottom of theback shell.
 29. The chair assembly of claim 26, wherein the recessextends about the entire central opening.
 30. The chair assembly ofclaim 26, wherein chair back assembly is movable between an uprightposition and a reclined position, and wherein the third portion of theback shell moves with respect to the frame as the back assembly is movedbetween the upright and reclined positions.